Hello everyone, new guy to the forum. I just picked up, for pretty much nothing, a Murray push mower with the Briggs & Stratton 550E series engine. I got it for nothing because the previous owner couldn't get it to start after being stored for the winter. So I went ahead and drained the oil and gas, cleaned the carburetor, put everything back together with fresh oil and gas, new spark plug, tried to start...nothing. Shot some starting fluid down the carb and it fired up and died, so I have spark. The carb isn't clogged because the compressed air goes through it like nobody's business. However....the primer bulb is doing absolutely nothing. The bulb itself is not cracked or rotted, but I did find a nipple right next to the main fuel line that appears to be part of the primer system. No hose connected to it and I can't seem to find where the hose would connect to. Any help would be great because I think fixing the primer system and being able to properly prime the carb would help me figure this thing out.
There's really no way it could attach to the primer bulb. Here's the back of the air cleaner assembly/primer bulb:
Now the small hole right above what I call the crosshairs is the back of the primer which lines up with the circular opening on the carb pictured here:
And in this shot you can see the white nipple on the carb with no line to it, which I suspect is the primer line, but I have zero clue where it would hook to. You would think the tank, since it needs fuel, but there is no other nipple on the tank besides the main fuel line.
Hopefully that helps someone see my dilemma a bit better. And whose idea was it to make a plastic carburetor? This is just dumb!
I have the EXACT same issues with the EXACT same model number and the EXACT same symptoms. I have also noticed that white nipple there. Press the primer bulb and gasoline squirts out.
Maybe a line fell off, but where does the other end of that missing pipeline from this nipple go? It could be that we have found a design flaw here...?
I'm hoping to take a trip to Wally Mart to see if this model is still on their showfloor. Then, I will examine where this missing part(?) should go? It may be a few weeks for me to go on this fact-finding mission, so if any else has this problem, and can make this recon, you could help many here.
I had one of the above engines come into the shop yesterday and looked at the nipple. There was nothing on it. After taking the carb apart and cleaning the jet in the bottom/side of the emulsion tower, it primed, started and ran as expected.
The hole in the end of the nipple on the one that I looked at was very small and didn't appear to leak air when the primer was pressed.
The nipple is a one way check valve and is used on other applications, although not on the Yard Machines push mowers being described. As a repair shop owner down in Georgia, I've been getting them in recently. I'm not fond of the all plastic carbs and people are having priming issues with them within the first few cuts. I came up with a "fix" for many that wont' prime well, even though the carb is clean and working correctly. I remove the rubber gasket at the intake on the carb, then slip and O ring over the port that primes. Then I press the rubber gasket back into place and tighten the intake to the carb before reinstalling the carb to make sure it went together right. Basically what this does it presses that area against the primer bulb much tighter. It seems these gaskets are prone to not sealing very well, and that weakens the priming action.
Yea, I figured the white nipple was for additional pollution control. I'm actually trying to make a video of this since there is only one on tube and does discuss that fuel input tower mentioned in this string. As far as the red bubble, You can check it for cracks buy holding the hole in the back to see if air gets through somewhere else. Whatever the case I figured out how to take that tower apart. I guess I didn't clean it good enough. Going at it again. Please advise. Same result now as guy above. manually shoot some gas in carb and run for a second to burn that but quits.
Took it all apart again and it was a tiny whole in the tower. Used canned air this time and felt felt and heard it clear against my hand. I'll eventually put the video on Youtube. Gotta get the grass cut. Neighbors been giving me dirty looks. At least they saw me cuss'n and throwing things at it half the day so they knew I was giving effort
